Some of the 13,000 cyclists riding in the 28th annual BP MS 150 bike ride make their way up a hill, Saturday, April 21, 2012, in Austin County. Cyclists, riding from Houston to Austin, are hoping to generate $17 million for MS research. ( Nick de la Torre / Houston Chronicle )

With two major outdoor events scheduled for the Houston area this weekend, security concerns are high following Monday's bomb attacks at the Boston Marathon.

The 29th annual BP MS 150 bicycle ride from Houston to Austin is scheduled to start at 6:45 a.m. Saturday from Tully Stadium. The two-day fundraiser for research on multiple sclerosis winds up in Austin at 6:30 p.m. Sunday.

And the 43rd annual Houston International Festival, a two-weekend celebration of international music, dance and food, kicks off at 11 a.m. Saturday near City Hall in downtown.

"Routinely, when we handle major events, depending on the size and circumstances, we always do a threat assessment," he said. "Based on the threat assessment, we determine if there are any vulnerabilities we need to address in planning."

Awareness level high

Storemski said festival organizers and city officials are asking the public to be vigilant and report anything suspicious, but they also want people to continue with their daily routine.

Debbie Pope, the National Multiple Sclerosis Society's regional vice president for development and marketing, said she couldn't discuss any concrete changes in security for the BP MS 150 but noted that the very nature of the event promotes safety awareness.

"People may notice a sense of heightened security, but we always do have quite a large security plan for the event because of the nature of it," Pope said Tuesday.

The organization is working with local, state and federal agencies as necessary to ensure safety of participants and spectators, she said.

Volunteers checked

"We've been in communication with them to lean on their expertise about what they'll be doing," Pope said. "These are all agencies and partnerships we've had for a long time."

Among other precautions, organizers do background checks on volunteers who are in "critical roles," she said.

More than 2,000 volunteers are expected to help with the event, which will have 12,000 riders, Pope said.

"We are moving a small village from Houston to Austin over two days," she said.

The annual ride is the national society's largest fundraiser and last year brought in $17.6 million.

This year's riders should monitor the ride's website at www.bpms150.net to watch for updates, Pope said.